dac960: return success instead of -ENOTTY

There is a missing break statement here.  This used to return directly
but we re-worked it in 2008 to add locking as part of the BKL push down.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/drivers/block/DAC960.c b/drivers/block/DAC960.c
index 9a13e88..0d3ffc5 100644
--- a/drivers/block/DAC960.c
+++ b/drivers/block/DAC960.c
@@ -7054,6 +7054,7 @@
 	else
 		ErrorCode =  0;
       }
+      break;
       default:
 	ErrorCode = -ENOTTY;
     }